Sheets or other webs of material are used in a variety of industries and in a variety of ways. These materials can include paper, multi-layer paperboard, and other products manufactured or processed in long webs. As a particular example, long webs of paper can be manufactured and collected in reels. These webs of material are often manufactured or processed at high rates of speed, such as speeds of up to one hundred kilometers per hour or more.
It is often necessary or desirable to measure one or more properties of a web of material as the web is being manufactured or processed. The measurements can be used by one or more process controllers to adjust the manufacturing or processing of the web. A process controller that implements model predictive control (MPC) or other model-based control can use one or more models to predict the future behavior of a web manufacturing or processing system. Control signals for adjusting the system are generated based on the predicted behavior of the system. The control of a property across a width of the web is referred to as cross-direction (“CD”) control, while the control of a property along a length of the web is referred to as machine-direction (“MD”) control.
CD control of a web is a difficult control problem when there are multiple actuator beams and multiple measurements in a web manufacturing or processing system. MPC or other model-based control could be used to address this problem. However, the tuning of an MPC or other model-based controller to achieve robust performance can be challenging for a number of reasons. One reason is that the tuning parameters typically available to users are not intuitive, and trial and error tuning attempts can be time-consuming and frustrating. Another reason is that automated tuning algorithms relying on robust control theory may require a user with an advanced understanding of control theory and involve abstract parameters.